79 runs hot
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Joined: Mar 2006
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From: west melbourne florida
79 runs hot
i have a 79 vette with dual elec fans and aluminum radiator and high flow water pump. and car still runs at 220 degrees. i even tested it with a heat gun can i take the thermostat out??? does it have to be in the car????? i live in florida and dont need heat or will it harm the heads??????
Team Owner
Joined: Aug 2006
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From: Columbia Missouri
Originally Posted by tellcom2001
i have a 79 vette with dual elec fans and aluminum radiator and high flow water pump. and car still runs at 220 degrees. i even tested it with a heat gun can i take the thermostat out??? does it have to be in the car????? i live in florida and dont need heat or will it harm the heads??????
Your flow is not the problem, at least not through the radiator anyway. It could be something as sinple as a blockage in the cooling passage. Have you ever flushed and cleaned the block?
An option you have is changing your cooling fluid. At auto part stores they sell a fluid, I can't recall any names right now, that replaces your anti-freeze. It's simple. You drain the system, pour in the new coolant, and teh rest with water. It'll generally give a 40 average degree drop.
One other option, is air flow through the engine compartment. At the top edge of teh hood, where the windshield meets it, is a lip or rib that seals down on the valance frame. This bulkhead is where a large pocket of hot air can get trapped and insulate teh engine a bit. A fix is to cut out several port holes for teh hot air to escape from. I used to pop the hood, but leave it latched. Just that extra space let out so much heat I saw a 30 degree drop.
Maybe try one of these and see what happens.
Team Owner
Joined: Aug 1999
Posts: 30,995
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From: Ontario
How many times does this question have to be posed?
http://forums.corvetteforum.com/show...1474971&page=8
http://forums.corvetteforum.com/show...1474971&page=8
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Originally Posted by paul67
How many times does this question have to be posed?
http://forums.corvetteforum.com/show...1474971&page=8
http://forums.corvetteforum.com/show...1474971&page=8
Make it a sticky if it pops up so much. Like general overheating troubleshooting?
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Joined: Jun 2006
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From: Atlanta GEORGIA
Originally Posted by tellcom2001
i have a 79 vette with dual elec fans and aluminum radiator and high flow water pump. and car still runs at 220 degrees. i even tested it with a heat gun can i take the thermostat out??? does it have to be in the car????? i live in florida and dont need heat or will it harm the heads??????
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
I have heard from several sources that water/coolant moving through the radiator too quickly will mean the heat transfer is limited, and you don't get effective cooling. The thermostat is there not only to allow the engine to heat up to opperating temp, but to restrict the water flow so the radiator can do it's job.
Think about it. The only part of the cooling system that actually releases heat is the rad. If the hot coolant SPRINTS through and back to the hot engine, you don't give it a chance to expell any heat through it.
If you really want to attack the thermostat, track down a high quality unit, not Oreilly or Autozone. Pay the extra money for it. I would suggest keeping a thermostat in the car, but make sure it works right.
I did that chemical coolant change a few years ag, and my engine operated all day at 180. Idle, hard running...no matter how long I have it out for. I haven't seen 200 since I did the fluid change.
Think about it. The only part of the cooling system that actually releases heat is the rad. If the hot coolant SPRINTS through and back to the hot engine, you don't give it a chance to expell any heat through it.
If you really want to attack the thermostat, track down a high quality unit, not Oreilly or Autozone. Pay the extra money for it. I would suggest keeping a thermostat in the car, but make sure it works right.
I did that chemical coolant change a few years ag, and my engine operated all day at 180. Idle, hard running...no matter how long I have it out for. I haven't seen 200 since I did the fluid change.
Burning Brakes
Joined: Aug 2005
Posts: 1,126
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From: Hudson Falls, N.Y. 76 Vette Modified L-48
Man, here we go again.....
OK...220*, obviously, everyone must agree is not good for the engine...
If he were to pull the stat out completely, and the temp drops to 190*, regardless if the fluid is going thru the rad too quickly, we have accomplished what we were trying to do....get the engine to the proper running temp.....
On the other hand, what if the temp drops to 160*?? Are we saying the stat was bad, restricting flow, and the rad is cooling TOO MUCH?
My feelings, in every other post we've tackled on this subject, is that a stat completely out would be the first move and see what happens and then if the temp is too low, add a quality stat....it just seems to me something is amiss with his system and if a lack of stat brings him to the target temp, no harm will be done....just my 2 cents..
OK...220*, obviously, everyone must agree is not good for the engine...
If he were to pull the stat out completely, and the temp drops to 190*, regardless if the fluid is going thru the rad too quickly, we have accomplished what we were trying to do....get the engine to the proper running temp.....
On the other hand, what if the temp drops to 160*?? Are we saying the stat was bad, restricting flow, and the rad is cooling TOO MUCH?
My feelings, in every other post we've tackled on this subject, is that a stat completely out would be the first move and see what happens and then if the temp is too low, add a quality stat....it just seems to me something is amiss with his system and if a lack of stat brings him to the target temp, no harm will be done....just my 2 cents..
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Originally Posted by kb2fzq
....it just seems to me something is amiss with his system and if a lack of stat brings him to the target temp, no harm will be done....just my 2 cents..
Exactly...
...I think taking out the stat would accomplish a temp decrease, but it's just a band aid on a broken arm. Something else is the problem. Clogged water jacket...scales causing hot pockets...I don't know what cleaning the jacket has had.
I do know that engine's cooling and heating systems are designed around the stat. A bad one will cause all kinds of problems. Before removing it altogether I think it'd be best to change to a good one, that he knows will provide proper flow.
Oh, and after looking over the first post again, I see you have a high flow pump. It could be that your fluid is already moving too fast, and a secondary problem is being made worse by this. Just a side thought.
Burning Brakes
Joined: Aug 2005
Posts: 1,126
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From: Hudson Falls, N.Y. 76 Vette Modified L-48
The problem troubleshooting here is we can only diagnose a problem from what the poster tells us about the problem....I agree there can be a litany of problems causing this, but we can only suggest the obvious...my point to start with a stat out would show us the far left condition, as we already now the far right condition....a very hot engine...starting in the middle, IMO, creates addition work...he might get lucky with the stat out...
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by kb2fzq
The problem troubleshooting here is we can only diagnose a problem from what the poster tells us about the problem....I agree there can be a litany of problems causing this, but we can only suggest the obvious...my point to start with a stat out would show us the far left condition, as we already now the far right condition....a very hot engine...starting in the middle, IMO, creates addition work...he might get lucky with the stat out...
Again, true. It's totally up to him. You suggest taking out the stat. Nothing wrong with him taking your advice.
I say replace the stat, and throw in a chemical coolant. Nothing wrong with him taking my advice.
It's totally up to him to inturpet our words of wisdom.
My 350 used to heat to 220. I saw it as high as 270. I did the chemical coolant change, put in a better stat, and viola...180 all day long. I'm not saying we had the same problem or that my fixes will work for him. That's why these are all just suggestions.
Burning Brakes
Joined: Aug 2005
Posts: 1,126
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From: Hudson Falls, N.Y. 76 Vette Modified L-48
Very true...all we can do is suggest a solution....270*????
WOW!!!
I am glad I run 190-195*, in every weather condition....one less problem to worry about....
Oh by the way, love your avatar
WOW!!!
I am glad I run 190-195*, in every weather condition....one less problem to worry about....
Oh by the way, love your avatar
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Originally Posted by kb2fzq
....270*???? WOW!!!
WOW!!!
Originally Posted by kb2fzq
Oh by the way, love your avatar
Race Director
Joined: Feb 2005
Posts: 16,100
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Originally Posted by tellcom2001
i have a 79 vette with dual elec fans and aluminum radiator and high flow water pump. and car still runs at 220 degrees. i even tested it with a heat gun can i take the thermostat out??? does it have to be in the car????? i live in florida and dont need heat or will it harm the heads??????
Are your temps of 220 at 65-70 mph by chance or in traffic..???
Rich
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Originally Posted by rihwoods
It is very important to keep the thermostat installed..but....you must match the type of stat with your "high flow pump"...go to Stewart Pumps site....they have very good information on this and much more...
Are your temps of 220 at 65-70 mph by chance or in traffic..???
Rich
Are your temps of 220 at 65-70 mph by chance or in traffic..???
Rich
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
Originally Posted by paul67
How many times does this question have to be posed?
http://forums.corvetteforum.com/show...1474971&page=8
http://forums.corvetteforum.com/show...1474971&page=8
Paul...what I find interesting is how much better the old GM stock thermal clutch fan worked (fully engaged at 190 F) as opposed to these new ones at 220 F.... in my case,anyway... 
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Originally Posted by rihwoods
Paul...what I find interesting is how much better the old GM stock thermal clutch fan worked (fully engaged at 190 F) as opposed to these new ones at 220 F.... in my case,anyway... I prefer fan clutch fans to fixed any day, and I don't have AC. I don't know if this is a good or bad thing, ut it seems to work fine for me. Mine's the stock '77 fan w/AC....I just yanked out the AC.